diff --git a/docs/changelog.txt b/docs/changelog.txt
index 7fbf560635..b45e459f9a 100644
--- a/docs/changelog.txt
+++ b/docs/changelog.txt
@@ -33,6 +33,7 @@ Template for new versions:
 ## Misc Improvements
 
 ## Documentation
+Document caveats about unit/item position fns w/r/t raiding units.
 
 ## API
 
diff --git a/docs/dev/Lua API.rst b/docs/dev/Lua API.rst
index 232daea9eb..64c4646121 100644
--- a/docs/dev/Lua API.rst	
+++ b/docs/dev/Lua API.rst	
@@ -1402,7 +1402,10 @@ Units module
 
 * ``dfhack.units.isActive(unit)``
 
-  The unit is active (non-dead and on the map).
+  The unit is active (non-dead and probably on the map). Unit must also be
+  present in the ``world.units.active`` vector to rule out raid missions. Use
+  ``utils.linear_index`` after this function returns true if you aren't
+  certain (i.e., not already iterating active units).
 
 * ``dfhack.units.isVisible(unit)``
 
@@ -1608,12 +1611,15 @@ Units module
 
 * ``dfhack.units.isUnitInBox(unit,x1,y1,z1,x2,y2,z2)``
 
-  Returns true if the unit is within a box defined by the
-  specified coordinates.
+  Returns true if the unit is within a box defined by the specified
+  coordinates. Make sure the unit is flagged active and is present in
+  ``world.units.active`` first, as the result may indicate that the unit
+  died or left the map here.
 
 * ``dfhack.units.getUnitsInBox(x1,y1,z1,x2,y2,z2[,filter])``
 
-  Returns a table of all units within the specified coordinates.
+  Returns a table of all units within the specified coordinates. Returned
+  units are guaranteed to be active (unlike ``isUnitInBox`` above).
   If the ``filter`` argument is given, only units where ``filter(unit)``
   returns true will be included. Note that ``pos2xyz()`` cannot currently
   be used to convert coordinate objects to the arguments required by
@@ -1643,7 +1649,9 @@ Units module
 
   Returns the true *x,y,z* of the unit, or *nil* if invalid. You should
   generally use this method instead of reading *unit.pos* directly since
-  that field can be inaccurate when the unit is caged.
+  that field can be inaccurate when the unit is caged. Make sure the unit is
+  active (and present in ``world.units.active``) first or else the result can
+  indicate where the unit died or left the map.
 
 * ``dfhack.units.teleport(unit, pos)``
 
@@ -2033,7 +2041,9 @@ Items module
 
   Returns the true *x,y,z* of the item, or *nil* if invalid. You should generally
   use this method instead of reading *item.pos* directly since that field only stores
-  the last position where the item was on the ground.
+  the last position where the item was on the ground. Make sure the item is present in
+  ``world.items.other.IN_PLAY`` first, otherwise the result can indicate where a unit
+  left the map with the item.
 
 * ``dfhack.items.getBookTitle(item)``
 
diff --git a/library/RemoteTools.cpp b/library/RemoteTools.cpp
index c8fc810c8b..79fcf7b225 100644
--- a/library/RemoteTools.cpp
+++ b/library/RemoteTools.cpp
@@ -584,7 +584,7 @@ static command_result ListUnits(color_ostream &stream,
 
     if (in->scan_all())
     {
-        auto &vec = df::unit::get_vector();
+        auto &vec = df::global::world->units.active;
 
         for (size_t i = 0; i < vec.size(); i++)
         {
diff --git a/library/include/modules/Items.h b/library/include/modules/Items.h
index 79aed92c36..0f797ae50e 100644
--- a/library/include/modules/Items.h
+++ b/library/include/modules/Items.h
@@ -137,7 +137,8 @@ DFHACK_EXPORT df::building *getHolderBuilding(df::item *item);
 // Get unit that holds the item or NULL.
 DFHACK_EXPORT df::unit *getHolderUnit(df::item *item);
 
-// Returns the true position of the item (non-trivial if in inventory).
+/// Returns the true position of the item (non-trivial if in inventory).
+/// Note: Make sure the item is in world.items.other.IN_PLAY first, else can be inaccurate.
 DFHACK_EXPORT df::coord getPosition(df::item *item);
 
 /// Returns the title of a codex or "tool", either as the codex title or as the title of the
diff --git a/library/include/modules/Units.h b/library/include/modules/Units.h
index 7eaa61ec62..0fd16bc3f9 100644
--- a/library/include/modules/Units.h
+++ b/library/include/modules/Units.h
@@ -69,7 +69,8 @@ namespace Units {
  * The Units module - allows reading all non-vermin units and their properties
  */
 
-// Unit is non-dead and on the map.
+/// Unit is non-dead and on the map (usually). Unit must also be present in world.units.active
+/// to rule out raid missions.
 DFHACK_EXPORT bool isActive(df::unit *unit);
 // Unit is on visible map tile. Doesn't account for ambushing.
 DFHACK_EXPORT bool isVisible(df::unit *unit);
@@ -174,12 +175,12 @@ DFHACK_EXPORT bool isDanger(df::unit *unit);
 // Megabeasts, titans, forgotten beasts, and demons.
 DFHACK_EXPORT bool isGreatDanger(df::unit *unit);
 
-// Check if unit is inside the cuboid area.
+// Check if unit is inside the cuboid area. Note: Make sure unit is truly active first, else can be inaccurate.
 DFHACK_EXPORT bool isUnitInBox(df::unit *u, const cuboid &box);
 DFHACK_EXPORT inline bool isUnitInBox(df::unit *u, int16_t x1, int16_t y1, int16_t z1,
     int16_t x2, int16_t y2, int16_t z2) { return isUnitInBox(u, cuboid(x1, y1, z1, x2, y2, z2)); }
 
-// Fill vector with units in box matching filter.
+// Fill vector with units in box matching filter. Note: Units guaranteed to be active.
 DFHACK_EXPORT bool getUnitsInBox(std::vector<df::unit *> &units, const cuboid &box,
     std::function<bool(df::unit *)> filter = [](df::unit *u) { return true; });
 DFHACK_EXPORT inline bool getUnitsInBox(std::vector<df::unit *> &units, int16_t x1, int16_t y1, int16_t z1,
@@ -202,7 +203,8 @@ inline auto citizensRange(std::vector<df::unit *> &vec, bool exclude_residents =
 DFHACK_EXPORT void forCitizens(std::function<void(df::unit *)> fn, bool exclude_residents = false, bool include_insane = false);
 DFHACK_EXPORT bool getCitizens(std::vector<df::unit *> &citizens, bool exclude_residents = false, bool include_insane = false);
 
-// Returns the true position of the unit (non-trivial in case of caged).
+/// Returns the true position of the unit (non-trivial in case of caged).
+/// Note: Make sure unit is truly active first, else can be inaccurate.
 DFHACK_EXPORT df::coord getPosition(df::unit *unit);
 
 // Moves unit and any riders to the target coordinates. Sets tile occupancy flags.
diff --git a/library/modules/Units.cpp b/library/modules/Units.cpp
index 44fec6ae2c..ee835f67af 100644
--- a/library/modules/Units.cpp
+++ b/library/modules/Units.cpp
@@ -667,7 +667,7 @@ bool Units::getUnitsInBox(vector<df::unit *> &units, const cuboid &box, std::fun
 
     units.clear();
     for (auto unit : world->units.active)
-        if (filter(unit) && isUnitInBox(unit, box))
+        if (isActive(unit) && filter(unit) && isUnitInBox(unit, box))
             units.push_back(unit);
     return true;
 }
diff --git a/plugins/spectate/spectate.cpp b/plugins/spectate/spectate.cpp
index 61584e8258..dd3e3b54be 100644
--- a/plugins/spectate/spectate.cpp
+++ b/plugins/spectate/spectate.cpp
@@ -202,6 +202,8 @@ namespace SP {
                 }
             };
             static auto valid = [](df::unit* unit) {
+                if (!Units::isActive(unit))
+                    return false;
                 if (Units::isAnimal(unit)) {
                     return config.animals;
                 }